SharePoint, to GAC, or not to GAC?

It's clear from these questions

When and when-not to install into the GAC?

What are the advantages and disadvantages of using the GAC?

To GAC, or not to GAC?

that it is not recommended to de开发者_如何学编程ploy assemblies to GAC as explained. So, I'm wondering why is the default of SharePoint solutions built using Visual Studio or WSP Builder is to deploy assemblies to GAC?

Various sharepoint components (besides just the site) won't be able to find it in the bin folder. See this other post for more details.

Does a SharePoint EventReceiver have to be installed in the GAC, and if so do all dependent assemblies have to as well?